Brake system



5 Sheets-Sheet l N. A. cHRlsTENsEN BRAKE SYSTEM Filed May 16, 1925 I IIIIJU.

Aug. 13,v 1929.

ATTORNEYS .Aug- 13, l929- l V N. A. cHRlsTENsEN 1,724,127

` BRAKE SYSTEM Filed May le, 1925 s sheets-S1166 2 /QLMZ-Q T Fun/ ATTORNEYJ Aug. 13, 1929. N. A. 'cHRlsTENsEN BRAKE SYSTEM Filed May 16. 1925 3 Sheets-Sheet NVENTOR,

AT T ORNEYs Patented Aug. l13, 1929.

. UNITED lSTATES NIELS A. CHRISTENSE, O F MILWAUKEE, WISCONSIN.

BRAKE SYSTEM.

Application. filed May 16,

The invention relates to brake mechanism for automotive vehicles. y

'The 'object of the invention is to provide a brake system for automotivevehicles in which control valve mechanism for the luidl pressure-operated brakes, including a trans-v mission brake,is associated with a foot-pedal which is also connected with tl'ie transmission brake for direct operation ofsaid brake by i0 the operator, should the' fluid-pressure in the brake system fail for any reason.

The invention further consists in the several features hereinafter set forth and more particularl defined by claims at the 2.3 conclusion hereo V- In the drawings: Fig. 1 is a plan view of a brake system embodying the invention;

Fig. 2 is a section taken on the line 2-2 of Fig. 1, the engine, transmission box and reservoir, shown in Fig. 1, being omitted;A Fig. -3 is an .enlarged elevation. view of certain parts shown in Fig. 1, with parts shown in'section;

Fig. 4 -is a plan view in Fig. 3; v

Fig. 5 is a detail sectional view taken on the line; 5 5 of Fig. 6;

lof the parts shown Fig. 6 is an enlarged elevation view of the transmission brake; 3o Referring to Figs. 1, 5 and 6, the trans- 4mission brake herein shown includes a pair of brake drums 7 arranged in spaced relation on the transmission shaft 8. 'Each of these drums has a lpair of brake shoes 9 associated therewith. Each shoe 9 carries a pin l0 intermediate its ends. A yoke 11 has the pins 1.0 for the shoes on one side of the drums pivotally mounted in it, and a yoke 12 has .the pins 10for the shoes on the other side of the drums pivotally-mountedin it.

The yokes 11 and 12 are carried on shafts 13, each pivotally mounted on a frame 14 which also provides a bearing 15 for the shaft 8 and which is mounted on a. shaft or frame member 16 secured at its ends to the main frame 17 ofcthe automotive vehicle.

' A lever 18 is pivotally connected at one end by a pin 19 to the lowerfend of yoke 12 and is pivota-ll connected by a pin -20 to a rod 21 exten ing through a borev in `a pivot pin 22 on lthe yoke 11. The rodv 21 has a nut 23 adj ustably mounted thereon and eiigageablel with the pin 22. An arm 24' of the lever 18 is connected by clevis links 25 land 26 to one arm of a bell crank lever 27 pivotally mounted on a pin on an arm 28 1925. seriaiNo. 30,832.

carried by the shaft 16. The other arm 29 E' of the lever 27 is adapted to be operated as hereinafter described, either by manual oi iiuid-pressure-operated means.

`With this construction, when-the arm 29 is swung toward the left the links 25 and 26 lare moved upward and this movement causes the lever 18 to swing the yoke 12 inwardly and at the same time exert a pull on the rod 2l to swing the yoke 11 inwardly toward `the drum, with the result that the brakeshoes 9, associated with these yokes, are applied to the drums. For releasing the shoes 9 on one side of the drums, a spring 30 is interposed between a lug 31 on the yoke and awnut 32 on thevbar 21 adjacent a nut 33 abutting a lug 34 on the frame 14, and for releasing the slices on the other side of the drums a spring 35 is interposed between said lug 34 andthe pin 22. The release position of the yoke 11 is determined by the adjustment of the nuts 23, 32 and 33.

drawings, the numeral 36 desi nates a footpedal, which may be, and pre erably is, the usual brake pedal of the vehicle, pivotally mounted at 37 and provided With a pin 38- mountedin slot 39 inthe end member 4() of a. link 41 whose other end member 42 is` `operation that takes place on thev manual 'operation of the transmission brake.

In order to operate the transmission brake by iluidpressure, I provide a brake cylinder 46 mounted on the frame of the vehicle and having a suitably packed piston (not shown), 0f known construction, working therein with its piston rod 47 projecting fionr'tliev .through a s lot 53l inthe member 45 to which it is pivotally connected. intermediate its Referring to Figs. 1k tov 4, inclusive, of the end of the arm 56. within the cylinder 59. between a seat n'leniher ends by a'y pin 54. Thus, when fluid-pressure 4is admitted to the brake cylinder 46 it will act on the piston therein, causing it to move the rod 47 outwardly and through the lever 50 produce a pullon. the link 41 similar to l the pull exerted by the downward movement of the pedal 36 by the operator, withl the re- 'valves of the br'ake system, the swinging of this arm serving to operate said valves.

The arm 56 is operatively connected with the pin 38 by alink 57 of the type which allows relative motion between the pedal 36and the' partsit actuates, and is shown-as formed by al rod 58 connected to the pin 38, acylinder 59 having a forked head member 60 secured thereto and pivotally connected to thesfree A spring 61 is mounted 62 on the rod 58 and the end 63 of the cylinder, the rod 58 being slidably mounted in a bore in the end 63 and albo're infthe end cap`- 64 of said cylinder. By vthis construction the movement of the rod 58 by the pedal is transmitted through the spring- 61 to the other part of the link, including the cylinder, so that the'link may move as a unit to operate the control valve mechanism through c the swinging of the arnr 56, and when said arm has reached the end ofyits travel further movement of the foot-pedal will cause the rod 58 to move relativeI to the cylinder A- 59 and in opposition to the spring 61.

- As in the aforementioned patent, the compressed air' reservoir 65,. which is supplied with compressed air in any suitable manner, as by a compressor (not shown) driven by the engine 66, is connected by a pipe 67 with the control valve mechanism, and when the inlet valve (not shown) thereof is opened by the forward lswing of the arm 56, compressed air is admitted intol the brake system and ppon the leturnof said arm the exhaust valve (not shown) of'said control mechanism is opened to release the air in the braker system. The brake system includes pipes 6 8, 69, 70 and 7l, thepipe 68 communicat ing with the pipes 69 and 7 0, and the pipe 71l communicating with the pipe 7 0 and with the head end of the brake cylinder 46. The pipe 69 has branch pipes 72 and the pipe 7() has branch pipes `73leading to the fhud-pressurey operated brake cylindersor motors 74, of the opposed piston type, which act upon the free ends of the brake bands-7 5 'associated with the brake drumsv 7 57;? on the front and rear i wheels. Each brake band is connected in-V termediate its ends by a link 76 to a support 76 on the steering knuckle/or rear axle housing, and is released. by springs 77- and 78.' *A further detailed showing of -this brake mechanismwillbe found in myUnited States Letters Patent No. 1,619,970, dated March 8, 1927.

As the particular brake mechanism for the front and rear wheels forms the subjectmatter of other applications heretofore'iiled by me, and as the system herein contemplates the use of any suitable brakeV mechanism `associated with these wheels, further descrip-4 tion thereof is not deemed necessary. t

From the foregoing description it will be noted that when the operator depresses the foot-pedal 36 the linkage 57 swings the armv 56 to ad'mit air intothe brake system and,`l

hence into the brake cylinder' 46, with the result that the link 41 is operated, as prewil.

ously described, to apply the transmission brake. Owing tov the lost motion connection between the pin 88 and the member 40,

by reason of the slot 39, the first motion of the foot-pedal will take up the usual slack in the lever system for the transmission brake, but at or -before the time this' slack is'taken up, the control valve mechanism will have been moved by the link 57 finto a position so as to admit air into the cylinder 46 as well as the cylinders 74, Iso-thatithe compressed air operates the transmission 'brake and the front and rear' wheel brakes.

As this application takes place, thev slot 39 takes care of the forward travel of the link 41due to the lair brake pressure, and as the air brake pressure is always stronger than the foot pressure this lost mot-ionwill al-V ways eause the outer end of the slotv 39 to keep in advance of thepin 38 so as to leavethe foot-pedal free to be manipulated for the air brake application and release only.

However, whenfor anylreason, there is a failure of air pressure inthe brake system, the foot-pedal will be moved forward to take up the slack andthetransmission brake will .be appliedv through the foot-pedal, as first described, by direct pull onthe brake 'rod ih,-

or link-4l 'without the assistance or intervention of` airv pressure. The footpedal travel for manual application ofthe brake 1s, in most' eases, longer thanwhen the air brakes are applied so that when-the mechanism of the foot-pedal control (valve has reached the limit of its travel the lost motion action of the link 57 comes into pla it being noted that the spring 61 is of su cient vstrength to permit a unitary movement of said link and yet sufficiently weakthat it can be readily compressed by the motion of the foot-pedal in the manual application of the shaft or transmission brakey so as to leave the brake rod 41, on a' manual applicavno tion, free to travel its full length without in any Way injuring the Working parts of the foot control valve. Since the first movement of the brake rod 44 by the brake cylinder 46 acts to take up slack in the transmission-brake-opei'ating means, and since the fluid-pressure motors for the vehicle wheels act directly on their brake members, the brakes for these Wheels Will be applied before the transmission brake is applied.

, The transmission brake may be located adjacent the rear axle housing, as shown and described in my copending application, Serial No. 715,752, filed May 24, 1924,

I desire it to be understood that this invention is not to be limited to any particular form or arrangement of parts'except in so far as such limitations are specified in the claims.

That I claim as my invention'is;

l. In a brake system for automotive vehicles, the combination of a transmission brake, and Wheel brakes, of iluid-pressure operated mechanism for actuating said Wheel brakes, Huid-pressure-operated mechanism for actuating said transmission brake, and

control-valve mechanism common to both,`

' .erated transmission brake and fluid-pressureoperated front and rear Wheel brakes, control-valve mechanism comm-on to all of Asaid brakes, operating means for said control valve mechanism, and mechanical means associated with said operating means and said transmission brake permitting a manual opveration of said transmission brake.

` 3. In a brake system for automotive vehicles, the combination of luid-pressure-operated front and rear Wlieel'brakes including brake cylinders for each Wheel brake having direct thrusting connection with the brake member for said Wheel, a transmission brake, a finid-pressure-operated motor, linkage connecting said last named motor to said trans- 'mission brake, manually-operated means associated with said linkage, control valve mechanism common to all of said brake cylinders, and operating means for said control valve mechanism associated with said manually operable means.

4. In a brake system for automotive vehinism for sa3 l brake cylinders, operating f means for said controlv valve .mechanism including an arm, a foot pedal and a yieldable link between said arm and foot pedal, and a connection between said foot pedal and saidV transmission brake for manually operating the same, including a lostl motion linkage permitting normal operation of said control valve mechanism.

In testimony whereof, I ailix my signature. I

NiELs A. oHRisTENsEN. 

